30 FEBRUARY 2024 WorldWide Drilling Resource® Drilling Fluid Maintenance II by Ronald B. Peterson Drilling Products Specialist, Mountainland Supply Company Drilling fluid properties need to be monitored or tested on a regular basis, and measures taken to maintain the desired properties. During the drilling process, the drilling fluid additives become the wall cake on the borehole; they also become attached to the cuttings and are removed by the solids control equipment. As they are removed, their concentration in the system decreases and the drilling fluid properties change. This includes all additives, bentonites, polymers, and surfactants. The drilled cuttings become finely ground and are incorporated into the drilling fluids which may make the visual appearance look similar and unchanged - and can mislead us into thinking the drilling fluids have not changed. Even though the flow properties appear to be the same, the water loss or filtrate and filter cake have probably changed. The solids control equipment will inadvertently remove some drilling fluid with the cuttings. In addition, the surface fluid level will drop as the cuttings are removed from the hole and replaced by drilling fluid. The typical reaction is to run a small stream of water to maintain the surface volume. This further reduces the concentration of desired additives in the drilling fluid and again changes the drilling fluid properties. If the original fluid had a specific concentration of each of the additives in it, any water additions should also have the same concentration of the specific additives. This can be accomplished by either adding the correct ratio of additives to water or through the use of a premix tank, which is my recommended method. We also need to remember some additives have been removed with the cuttings and will need to be replaced as well. Monitoring the fluid properties will help you to determine the amount needed to sustain the original properties. More to come in future articles. This article is the second of a series of articles where we will address this critical portion of the drilling process. Watch for the continuation of this series in future issues. We will discuss the drilling process and its effect on the drilling operation and drilling fluid. Feel free to chip in with any comments or concerns you have. Please submit any questions to WWDR - contact Michele (below) and she will get them to me. Remember, this is your resource and can only provide information you need and can use if we have your input. Thank you for all you do and for your dedication and support. Thanks for reading. As I often say, “A man has to know his limitations.” Working together, it is amazing where we can go. Enjoy the trip. Ron Ron Peterson may be contacted via e-mail to michele@worldwidedrillingresource.com WTR Foundations by: American Society of Civil Engineers Deep Foundations: Design, Construction, and Quality Control March 7-8 ~ Reston, VA phone: 703-295-6300 asce.org Irrigation by: Rain Bird Academy Training March 12-14 ~ Columbus, OH March 26-28 ~ Atlanta, GA phone: 800-498-1942 E-mail: training@rainbird.com More education opportunities during events can be found by clicking here online at: worldwidedrillingresource.com Education Connection
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